There is a growing market demand for inexpensive environmental monitors for both research and personal health. Poor environmental conditions such as toxic air pollutants and the chemicals that form acid rain and ground-level ozone can damage trees, crops, wildlife, and bodies of water. Airborne particulate matter is among the deadliest forms of air pollution. Increased concentration of particulate matter below PM10 greatly increases risk of lung cancer with no safe minimum level. Asthma, cardiovascular disease, respiratory diseases and birth defects have also been associated with increases in airborne particulate matter concentration.
These conditions are also a detriment to the economy, resulting in thousands of workers on sick leave per day and billions of dollars lost due to reduced yields of agricultural crops and strain on health care systems around the world. Environmental researchers often do not have the budget to purchase multiple devices to develop data maps in order to monitor these adverse environmental conditions.
There is also a growing interest for consumers to gauge their overall health and collect personal environmental exposure statistics. Poor environmental conditions are a concern for those with health problems such as people with sensitive respiratory systems or the elderly with heart diseases. Environmental trackers may be used for monitoring these conditions at home, in the office, during a commute or exercise routine.
Environmental data would typically include air quality, temperature, humidity, pressure, visible light and ultra-violet (UV) radiation. Light scattering aerosol spectrometers (LSAS) are typically used to measure airborne particles, which can aggravate health problems and cause throat irritation and breathing difficulties. Thermistors, thermocouples or resistance temperature detectors are typically used to monitor temperatures and communicate with the software to warn the user if there is an increased risk of heat stroke due to high ambient temperatures. Developments in microelectromechanical systems (MEMS) have made measuring humidity and pressure simple tasks that can be done with cost-effective off-the-shelf integrated circuits, MEMS Hygrometers are used to measure humidity; low humidity levels may lead to skin irritation and excessive dehydration, MEMS Barometers are used to measurement atmospheric pressure which can be indicative of changing weather conditions. Photodiodes can be used to measure UV and visible wavelength radiation. Extended and unprotected exposure to UV radiation is known to increase the risk for skin cancer. A LSAS can use humidity and temperature measurements to increase its accuracy.
Conventional techniques for measuring environmental conditions are limited by single-function monitors. Multiple devices would be required in order to measure air quality, temperature, humidity, pressure, and UV radiation. The collected data would be on separate platforms; many of which are devices and not intended to be carried around for extended periods.
Increased affordability for these sensors combined with improvements in battery, wireless and mobile computing have created conditions for the development of a low cost wearable environmental sensor. A wearable device typically is worn daily as an accessory like a watch or jewelry. Existing wearable devices are often bulky, uncomfortable, and are only able to measure a one or two environmental parameters. They typically have relatively large plastic enclosures and are not suitable for carrying around for extended periods, let alone allowing the user to wear the device and have freedom of movement during typical daily activities. Additionally, existing wearable devices are typically limited to a single user and do not support analyzing data from multiple users to create regional data maps.
There are multiple possible use cases for this technology. In one use case, the user may operate the device primarily as a personal self-monitoring health device. The user may wear the device and check the measurements throughout the day. The device will infrequently store the measured data to on-board memory and frequently sync the measured data with the application. In the second use case, the user may operate the device primarily in the research industry. The user may install the device in a certain location, leave it for a number of hours, days, or weeks, retrieve the device after this period, then sync the data with the application. The device will frequently store the measured data to on-board memory and infrequently sync the measured data with the application. This patent will focus primarily on the first use case. The alternate embodiment of the invention is the device that fulfills the second use case.
Current methods of environmental monitoring may be expensive, laborious or inconvenient. Accordingly, this results in a need for a low cost, effective method for monitoring and tracking environmental conditions.